The sequence of a large L1Md element reveals a tandemly repeated 5' end and several features found in retrotransposons

• Published in: Molecular and cellular biology Vol. 6; no. 1; pp. 168 - 182
• Main Authors: Loeb, D D, Padgeet, R W, Hardies, S C, Shehee, W R, Comer, M B, Edgell, M H, Hutchinson, CA III
• Format: Journal Article
• Language: English
• Published: 01-01-1985
• ISSN: 0270-7306

The complete nucleotide sequence of a 6,851-base pair (bp) member of the L1Md repetitive family from a selected random isolate of the BALB/c mouse genome is reported here. Five kilobases of the element contains two overlapping reading frames of 1,137 and 3,900 bp. The entire 3,900-bp frame and the 3' 600 bp of the 1,137-bp frame, when compared with a composite consensus primate L1 sequence, show a ration of replacement to silent site differences characteristic of protein coding sequence. The relative organization of the 1,137- and 3,900-bp reading frames, which overlap by 14 bp, bears resemblance to protein-coding, mobile genetic elements. Homology can be found between the amino acid sequence of the 3,900-bp frame and selected domains of several reverse transcriptases. The 5' ends of the two L1Md elements described in this report have multiple copies, 4 2/3 copies and 1 2/3 copy, of a 208-bp direct tandem repeat. The sequence of this 208-bp element differs form the sequence of a previously defined 5' end for an L1Md element, indicating that there are at least two different 5' end motifs of L1Md.